What is it called when base units are combined, such as g/mL for density?

Correct Answer: B

Rationale: The correct answer is B: derived units. When base units (such as grams or milliliters) are combined, as seen in g/mL (grams per milliliter) for density, they form derived units. Derived units measure complex quantities that are derived from combinations of base units. Choice A, 'combined units,' is incorrect as it does not specifically refer to the formation of new units from base units. Choice C, 'base units,' is incorrect because base units are the fundamental units from which all other units are derived, not the combinations of units. Choice D, 'calculated units,' is incorrect as it does not accurately describe the concept of combining base units to form a new unit like g/mL for density.

Correct Answer: C

Rationale: To convert liters to milliliters, you need to multiply by 1000 since there are 1000 milliliters in 1 liter. Therefore, 3.75 liters x 1000 = 3750 milliliters. This means that option C, 3750 ml, is the correct conversion. Choices A, B, and D are incorrect because they do not reflect the correct conversion from liters to milliliters.

Correct Answer: A

Rationale: The correct formula to convert Celsius to Fahrenheit is (C 9/5) + 32. This formula involves multiplying the Celsius temperature by 9/5 and then adding 32 to get the Fahrenheit temperature. Choice B is incorrect as it suggests dividing by 5/9 instead of multiplying by 9/5. Choices C and D are both incorrect because they involve using the Fahrenheit temperature in the calculation, which is not the correct method for converting Celsius to Fahrenheit.

Correct Answer: B

Rationale: To convert kilograms to grams, you need to multiply by 1000 since there are 1000 grams in a kilogram. Therefore, 2 kilograms is equal to 2 x 1000 = 2000 grams. Choice A (200 grams) is incorrect as it represents the value of 0.2 kilograms. Choice C (20 grams) is incorrect as it represents the value of 0.02 kilograms. Choice D (2 grams) is incorrect as it represents the value of 0.002 kilograms.